There is a GUI around here that let's you copy all your files on one wbfs drive to another wbfs drive via PC. It's the wbfs-tool (current version is 1.0.13 i think). Search for it in the board. Hope it helps you. As far as i know it's the only GUI around here that offers this option.

I would say it works, BUT:
the data isn't copied directly. It's simply a batch job to extract data from the first Disk to an .ISO in a temp dir and then this .ISO gets installed on the second HDD.
I'm rather disappointed about this, because this point why the "copy process" lasts a very long time for a game with a size of 180MB (cause 180MB => 4.3 GB, 4.3GB => 180MB)
After some thinking about it, I found that the problem is the WBFS.EXE, that doesn't support direct copy.
So maybe someone can implement this feature into the WBFS.EXE